Polar electromagnet devices including a permanent magnet are known. An electromagnetic relay including such an electromagnet device is disclosed in, e.g. PTL 1. A conventional electromagnetic relay disclosed in PTL 1 includes a contact mechanism unit including a fixed contact and a movable contact, and a driving mechanism unit including an electromagnet block (an electromagnet device). The electromagnet block has a spool, a driving shaft, a movable core, and a fixed core. A coil is wound around the spool. The driving shaft is inserted into a center hole of the spool and is reciprocatably moveable in a shaft center direction. The movable core is attached to one end of the driving shaft and is attracted to the fixed core upon energization of the coil. The movable core is provided unitarily with the permanent magnet on the same shaft center.
In this electromagnetic relay, a voltage applied to the coil moves the movable core to the fixed core due to a resultant force of an attractive force of the fixed core on the movable core and a repulsive force of the permanent magnet against a magnetic flux of the coil.